Along with his team at the Harvard-Smithsonian Center for Astrophysics, he has located three exoplanets, planets outside our solar system that orbit a sun, including the smallest identified to date. But when he is not searching the universe for new planets, Johnson is a leading advocate for diversity in the sciences.

In 2014, he established the Banneker and Aztlán Institute, "an ambitious new program meant to increase the number of black and Latino astronomers in the field and to ensure that they are equipped to grapple with the social forces they will face in their careers." (Smithsonian.com) Johnson will bring his story of challenging the lack of diversity in the sciences to Southern Miss when he speaks at the University Forum on February 20 at 6:30 p.m. in Bennett Auditorium.